It's still changing... Remember the recent Czech Republic versus Slovakia split up? Then prior to that all the new borders and countries in the former USSR when Communist Russian gave up. This has been going on longer than 1,000 years. Remember the Roman empire breakup and before that, all the different territories from the Greek peninusula.

Even Native Americans didn't care about or use borders. In fact, the white man (mostly coming from Europe) is the one that put borders around the tribes as if they cared. And they fixed them when they sent them to reservations that have their own borders.